Investors interested in stocks from the Medical Info Systems sector have probably already heard of Cerner (CERN) and Omnicell (OMCL). But which of these two companies is the best option for those looking for undervalued stocks? Let's take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.Both Cerner and Omnicell have a Zacks Rank of # 2 (Buy) right now. This means that both companies have witnessed positive earnings estimate revisions, so investors should feel comfortable knowing that both of these stocks have an improving earnings outlook. But this is just one piece of the puzzle for value investors.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category grades stocks based on a number of key metrics, including the tried-and-true P/E ratio, the P/S ratio, earnings yield, and cash flow per share, as well as a variety of other fundamentals that value investors frequently use.CERN currently has a forward P/E ratio of 21.78, while OMCL has a forward P/E of 46.11. We also note that CERN has a PEG ratio of 1.63. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. OMCL currently has a PEG ratio of 2.88.Another notable valuation metric for CERN is its P/B ratio of 5.49. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, OMCL has a P/B of 6.92.Based on these metrics and many more, CERN holds a Value grade of B, while OMCL has a Value grade of D.Both CERN and OMCL are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that CERN is the superior value option right now. Investor Alert: Legal Marijuana Looking for big gains? Now is the time to get in on a young industry primed to skyrocket from $13.5 billion in 2021 to an expected $70.6 billion by 2028. After a clean sweep of 6 election referendums in 5 states, pot is now legal in 36 states plus D.C. Federal legalization is expected soon and that could kick start an even greater bonanza for investors. Zacks Investment Research has recently closed pot stocks that have shot up as high as +147.0%. You’re invited to immediately check out Zacks’ Marijuana Moneymakers: An Investor’s Guide. It features a timely Watch List of pot stocks and ETFs with exceptional growth potential.Today, Download Marijuana Moneymakers FREE >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Cerner Corporation (CERN): Free Stock Analysis Report Omnicell, Inc. (OMCL): Free Stock Analysis Report To read this article on Zacks.com click here.